1022-13-5Relevant articles and documents
Reactions of 7-Chloro-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2,2-dioxide in Various pH Solutions
Yang, Shen K.
, p. 635 - 642 (1998)
Diazepam (1) is a frequently prescribed hypnotic/anxiolytic drug worldwide. 7-Chloro-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2,2-dioxide (2) is an initial alkaline hydrolysis product of 1. The mechanisms in the conversion of 2 to 2-methylamino-5-chloro-α-(phenylbenzylidene)glycinate (3), 2-methylamino-5-chlorobenzophenone (4), and 1 in aqueous solutions with pH ranging from 0 to 12.2 is the subject of this report. Results of temperature-dependent hydrolysis kinetics and product identification indicated that: (1) in solutions with pH between 7 and 12.2, 2 underwent a ring-opening reaction to form 3; the rate decreased with increasing pH. (2) In solutions with pH between 2 and 7, 2 was rapidly converted to 3, followed by a pH-dependent conversion to 4; the rate increased with decreasing pH and became less sentitive to pH at pH ≤ 4.5. (3) In solutions with pH between 0 and 2, 2 was rapidly converted to 4 and 1; the percentage of 1 increased with decreasing pH. (4) A 2 containing one oxygen-18 atom lost 50% of its oxygen-18 following conversion to 1 in 1 M HCl. In addition to understanding the mechanism in the transformations of 2 in various pH solutions, this study established a simple and efficient method in the quantitative conversion of 1 to 4 and in the preparation of an oxygen-18-containing 1 at C2 position.
Phase transfer catalysed N-monoalkylation of amino anthraquinones
Ramrao,Ramkumar,Anant,Ramanuja
, p. 1129 - 1135 (1991)
1-Alkylaminoanthraquinones (2a-f) and 1,4-bisalkylaminoanthraquinones (4a-c) were prepared from aminoanthraquinones (1,3) by alkylation with alkyl sulphate/alkyl halide in presence of powdered sodium hydroxide, potassium carbonate and phase transfer catalyst.
High-performance liquid chromatographic method for assay of otilonium bromide, diazepam, and related compounds in finished pharmaceutical forms
Mannucci,Bertini,Cocchini,Perico,Salvagnini,Triolo
, p. 367 - 370 (1993)
A rapid, simple, stability-indicating assay procedure for otilonium bromide, a smooth muscle relaxant agent, and diazepam in composite tablet analysis was developed with high-performance liquid chromatography. The tablet matrix was dissolved with water, and drugs were extracted with acetonitrile containing an internal standard. An aliquot was centrifuged and chromatographed on a 5-μm, reversed-phase column with 0.5 M sodium acetate trihydrate buffer containing 5 mM 1-heptanesulfonic acid monohydrate sodium salt:methanol (30:70; v/v; adjusted to pH 6.0 with glacial acetic acid) as the mobile phase. The selectivity of the chromatographic system was demonstrated by resolving both compounds from various potential degradation products of each compound. The method is linear, quantitative, and reproducible.
Hydrolysis of temazepam in simulated gastric fluid and its pharmacological consequence
Tian Jian Yang,Quan Long Pu,Yang
, p. 1543 - 1547 (1994)
Temazepam (TMZ), a hypnotic and anxiolytic drug, underwent hydrolysis in simulated gastric fluid (SGF; pH 1.2). The hydrolysis reaction of TMZ in acetonitrile:SGF (1:19, v/v) at 37 °C was an apparent first-order reaction, with a half-life of 5.47 ± 0.17 h (i.e., ~12% of the remaining TMZ was hydrolyzed per hour). The predominant hydrolysis product (2'-benzoyl-4'- chloro-N-methyl-2-amino-2-hydroxyacetanilide) and a minor hydrolysis product [2-(methylamino)-5-chlorobenzophenone], derived from acid-catalyzed reaction of TMZ in an aqueous solution, were characterized by ultraviolet-visible absorption mass, infrared, and proton nuclear magnetic resonance spectra analyses. The kinetics of the hydrolysis reaction were studied as a function of acid concentration, temperature, and ionic strength and in deuterated solvent. Results indicated that the predominant hydrolysis reaction at pH ? pK(a) (1.46) was caused by protonation at N4, followed by a nucleophilic attack by water at C5 of the C5-N4 iminium ion and a subsequent ring-opening reaction. Pharmacological activity tests in mice indicated that the predominant hydrolysis product of TMZ was inactive. The results suggest that a fraction of an orally taken TMZ may be inactivated by hydrolysis in the highly acidic gastric fluid.
Ru-Catalyzed Selective Catalytic Methylation and Methylenation Reaction Employing Methanol as the C1 Source
Biswas, Nandita,Srimani, Dipankar
, p. 10544 - 10554 (2021/07/31)
Methanol can be employed as a green and sustainable methylating agent to form C-C and C-N bonds via borrowing hydrogen (BH) methodology. Herein we explored the activity of the acridine-derived SNS-Ru pincer for the activation of methanol to apply it as a C1 building block in different reactions. Our catalytic system shows great success toward the β-C(sp3)-methylation reaction of 2-phenylethanols to provide good to excellent yields of the methylated products. We investigated the mechanistic details, kinetic progress, and temperature-dependent product distribution, which revealed the slow and steady generation of in situ formed aldehyde, is the key factor to get the higher yield of the β-methylated product. To establish the environmental benefit of this reaction, green chemistry metrics are calculated. Furthermore, dimerization of 2-naphthol via methylene linkage and formation of N-methylation of amine are also described in this study, which offers a wide range of substrate scope with a good to excellent yield.
Synthesis method of 2-methylamino-5-chlorobenzophenone
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Paragraph 0021; 0022; 0023; 0024; 0025, (2018/07/30)
The invention discloses a synthesis method of 2-methylamino-5-chlorobenzophenone. The method includes the steps of: subjecting an aqueous solution of N-methyl-3-phenyl-5-chloro-2, 1-benzisoxazole methyl quaternary ammonium salt (II) and a hydrazine hydrate aqueous solution to reduction reaction under the catalysis of zinc chloride to obtain 2-methylamino-5-chlorobenzophenone (1). Compared with theexisting synthesis methods, the method provided by the invention has the advantages of simple synthesis method, high catalytic activity, easy separation and purification of product, high product purity, high yield, low emission of three wastes, small environmental pollution and the like, and is suitable for industrial production.
Transition-Metal-Free Synthesis of Acridones via Base-Mediated Intramolecular Oxidative C?H Amination
Wei, Wen-Tao,Sheng, Jian-Fei,Miao, Hui,Luo, Xiang,Song, Xian-Heng,Yan, Ming,Zou, Yong
, p. 2101 - 2106 (2018/06/14)
Intramolecular oxidative C?H amination of 2-aminobenzophenones was achieved in the presence of potassium tert-butoxide and dimethyl sulfoxide. A series of functionalized acridones were prepared in moderate to excellent yields in a mild, efficient, and transition-metal-free manner. (Figure presented.).